Storage tank for cold liquids

ABSTRACT

855,520. Storing liquefied gases. CONCH INTERNATIONAL METHANE Ltd., [formerly CONSTOCK INTERNATIONAL METHANE Ltd.]. July 1, 1959 [July 9, 1958(2)], No. 22632/59. Class 8(2). A liquefied gas storage tank 10, Fig. 1, is built of rectangular heat insulation panels 28 lined by a liquid impervious cup-shaped member 62 resting on the base of the shell and having its sides supported against collapse by vertically spaced horizontally extending spiders 96, 98 and cables 110, 112. Vertical wooden external reinforcing ribs 16, Fig. 2, have their ends 24 engaged in upper and lower wooden rings 14 and are bolted at intermediate points to vertical planks 36, Fig. 3, which are in turn bolted at 42 to adjacent panels 28. The lining 62 comprises a bottom plate 64 of metal plastic or glass fibre and side plates 66 having overlapping edges 80, 78, Fig. 5, projecting into the storage chamber 30 over a wooden insert 83 set in the bottom panel 28. Adjacent edges 68, 70, Fig. 4, of side plates 66 similarly overlap and form expansion joints held against creep by wooden keys 74 set in the panels 28. The upper spider 96 comprises wooden inner and outer rings 100, 102 connected together by wooden radial arms 104. The inner ring 100 is supported by steel cables 110 whilst the outer ring 102 presses against the lower face of a flanged steel ring 86. bolted to the insulation panels 28 and serving to support the upper edge of the uppermost plates 66 of the lining 62. The lower spiders 98 have upwardly directed radial arms connecting inner and outer rings the latter being supported by cables 112 connected to the flanged ring 86. A displaceable core 126 in the uppermost panel 28 allows for pressure relief. In a modification a base panel 218, Fig. 8, is splined to side panels 228 in which are inserted hardwood portions 248 and around which are located steel retaining bands 246. Prevention of collapse of lining 262 is effected by horizontal wooden rings 282 connected together by vertical wooden columns 284 and crossbraces 290 ; each of the rings 282 having a groove 286, Fig. 11, loosely engaged by an inwardly projecting flange of a steel ring 276 rigidly connected to adjacent edges of lining plates 266. The latter have corrugations 278 to allow of thermal expansion.

Nov. 3, 1959 c. D. DOSKER STORAGE TANK 30R cow LIQUIDS 2 Sheets-Sheet 1Filed July 9, 1958 FIG. 1

INVENTOR. orfleizus D Das/zer Nov, 3, 1959 2 Sheets-Sheet 2 Filed July9, 1958 I r T 0 m w h. w ww d 8 n n fl g m; 8 6 5 5 L a b N a w age andtransportation problems arise. rectly contacted by the cold liquid mustbe of special construction to withstand the extremely coldtemperasronaon TANK FOR corn mourns Cornelius D. Dosker, Iiouisville,Ky., assign'or to Constock International Methane Limited, Nassau,Bahamas, a corporation of Bahamas Application July 9, 1958, Serial No.747,413

14 Claims. (Cl. 220-11) This invention relates, as indicated, toimprovements in tanks used for storing cold liquids, and moreparticularly, but not by way of limitation, to an improved land-basedstorage tank for storing liquefied natural gas.

Many occasions arise whenit is desirable to store natural gas in aliquefied state for variable periods of time. For example, in thoseareas having a natural-gas shortage and being supplied with natural gasfrom a reform at equivalent'pressure, it is most desirable to storethe'natural gas in a liquefied state at the point of use.

In addition to the above, an industry is now in the stageof developmentfor the primary purpose of shippingnatural gas to localities whichcannot be economically reached by pipeline'from the source of naturalgas supply. The naturalgas could be transported to the remoteloc alitiesin a gaseous form by use of ships and the like. However, and as notedabove, natural gas in gaseous form-occupies so much volume as to'maketransportation thereof in this form impractical. Therefore,.

the'natural gas is liquefied at or near the source of supply 'andtransported in a liquefied state to the remote locality forrevaporization and use as a fuel. It is highly desirable to maintain asupply of the gas in a liquefied state both at or near the source ofsupply and at or near I the point of use. Such storage involves unusualproblems, principally due-t the fact that liquefied natural gas hasatemperature of from 240 to 258 F. at,,or slightly above, atmosphericpressure, the pressure at which the -liquefied natural gas-is normallytransported as well as stored at the source of supply and the point ofuse.

When storing a cold liquid such as liquefied natural gas in theconventional manner by use of a metal tank simply surrounded with aninsulating material, 'bothstor- The metal ditures, with the metalusually" being stainless steel or aluminum; Such metals are, of course,expensive when compared with more conventional plate steel tanks. Also,I such a metal tank must of necessity have suflicient strength.

to befs'elf-supporting and contain the volume of liquid desired to bestored, thereby requiring not only an ex pensive installation,- but also,a serious transportation problem in transporting the tank to the pointof use. It may also be noted that such a tank will be subjected tosubstantial expansion and contraction by the substantial temperaturechanges in the tank, which variations .'-in the dimensions of the tanksoon render most popular United States Patent 0" 2,911,125 Patented Nov.3, 1959 insulating materials, such as the fibrous insulating materials,inoperable.

invention contemplates the: construction of such a tankprincipally outof wood to provide a light-weight structure which may be easilyassembled at the point of useand easily transported to the point of use.The side walls of the tank are preferably formed out of insulating woodpanels sealed in side-by-side relation around the periphery of the tankto provide a self-supporting and efiective insulation barrier. Thebottom of thetank is also preferably formed out of the same material. Arelatively thin lining extends around the inner periphery of the tankand over the bottom of the tank to provide a storage chamber forreceivingthe liquefied natural gas. The

. lining is not bonded to the inner surface of the insulating panels andis usually not self-supporting. I therefore contemplate the use of anovel supporting structure positioned within the lining to retain thelining in the desired position in the tank, without interfering wthexpansion and contraction of the lining resulting from the temperaturechanges when the tank is emptied and filled with the cold liquefiednatural gas.

An important object of this invention is to provide a light-weight andeconomical tank for storing cold liquids.

Another object of this invention is to provide a tank for storing coldliquids which may be transported to the point of use disassembled, andthen easily assembled in the field at the point of use. i

A further object of this invention is to provide a novel tank forstoring cold liquids having a separate and relatively thinlining forreceiving the cold liquid, without the use of an outer supporting metalshell or a cumbersome framework. I

A stillfurther object of this invention is to provide a novelnon-self-supporting lining in a storage tank used for storing coldliquids, and a novel'supporting structure fora-retaining the lining inthe desired position in the tank.

Other objects and advantages ofthe invention will be evident from thefollowing detailed description, when read in conjunction with theaccompanying drawings which schematically illustrate my invention.

In the drawings:

Figure 1 is a vertical sectional View through a tank constructed inaccordance with this invention;

Figure 2 is a detailed horizontal sectional View through a typicalportion of the side walls of the tank illustrated in Fig. 1; 1

Figure 3 is a vertical sectional view through a portion of the bottom ofthe tank shown in Fig. l illustrating the connection of the bottom ofthe lining to the bottom of the tank;

Fig. 4 is an enlarged sectional view througha portion of the liningillustrating the construction of the lining and the support for thelining; and 1 Figure 5 is a view similar to Fig. 4 illustrating amodified construction.

Referring to the drawings in detail, and particularly Fig. 1, referencecharacter 10 generally designates the entire tank structure whichincludes a base ring 12 supported on suitable footings 14' spacedcircumferentially around; the base ring to support the major portion ofthe weight of the tank structure 10 and the contents of the near theouter periphery of the ring to provide an upwardly facingshoulder 16."Normally, the ring .12 will be of substantially circular configuration,although it will be understood that the ring 12' may have any desiredconfiguration, such as an oval shape or a polydiagonal shape, such as anoctagon. The bottom ,18 of the tank rests on the top of the ring 12 andpreferably comprises a plurality of insulating wood panels extendingdiagonally across the ring 12 and sealed in side-by-side relation toprovide a continuous bottom wall for the tank. Each of the insulatingpanels comprising the bottom 18 is preferably constructed with aninsulating wood layer 20 of substantial thickness, with sheets ofhardwood 22 on the upper and lower faces of the insulating wood 20. Theinsulating wood layer 20 may be, for example, balsa or quippo wood andthe sheets 22 may be formed out of a hard plywood. The bottom 18 isadditionally supported by a suflicient number of footings 24 and woodpads 26 providing cushions between the bottoms of the panels comprisingthe bottom 18 and the footings 24.

The vertical side Walls of the tank 10 are formed by use of a pluralityof vertically extending insulating panels 28 extending upwardly fromaround the periphery of the bottom 18 and sealed in side-by-siderelation to provide a continuous insulating barrier around the peripheryof the tank. The lower end of each panel 28 is notched at 30 to matewith the upwardly facing shoulder 16 extending around the base ring 12and support the panels 28 directly on the base ring 12. Also, the lowerend portions of the panels 28 are secured to the outer periphery of thebottom 18 by suitable splines or keys 32 extending into mating groovesin the panels 28 and theends 'of the panels comprising the bottom 18. Asealing compound (not shown) may be provided between the contactingsurfaces of the vertical panels 28 and the bottom 18 to provide anuninterrupted insulation around the sides and bottom of the tank 10.

The panels 28 are suitably constructed to be selfsupporting, that is,the panels 28 are of suflicient strength to support at least their ownweight without collapsing and without appreciably bending. I prefer toconstruct the panels 28 in the same manner as the panels comprising thebottom 18, that is (see Fig. 2), with a relatively strong layer 34 of aninsulating wood, such as balsa or quippo wood, and hardwod sheets 36bonded over the inner and outer faces of the layer 34. When the tank 10is formed with a generally circular horizontal cross section, the panels28 are curved transversely, as indicated in Fig. 2, with the panels inside-by-side abutting relation. I also prefer to insert a strip ofhardwood 38 in each side edge of each panel 28 throughout the length ofthe respective panel, with the outer face of each strip 38 being taperedat 40 from the inner surface of the respective panel. The tapers 40 ofadjacent strips 38 are extended in opposite directions to form a taperedgroove for receiving a tapered strip 42 of relatively soft wood, such asbalsa wood. Each strip 42 extends throughout the length of the panels 28and is wedged against the respective mating tapers 40 to provide aneffective seal between adjacent panels 28 and to provide an expansionjoint between adjacent panels 28. When cold liquid is stored in thetank, as will be hereinafter described, the inner portions of the panels28 will become substantially colder than the outer portions of thepanels, thereby causing the inner portions, particularly, of the panelsto contract and expand. The strips 42 accommodate this relative movementbetween adjacent panels to provide an expansion joint and maintain aneffective seal between the adjacent panels. I also prefer to extend asealing strip 44 formed out of rubber or the like through mating groovesin the mating faces of each pair of strips 38 outwardly of the strips 42to further assure that a seal will be main- 4 tained between adjacentpanels when the tank is filled with a cold liquid.

The vertical panels 28 are retained in assembly and provided withadditional radial strength by use of a plurality of vertically spacedretaining bands 46 encircling the panels 28, as illustrated in Fig. 1.The bands 46 may be formed out of any desired metal, such as steel,since they will not be exposed to any substantial temperature changes.The bands 46 are suitably secured around the tank in relatively tightengagement with the outer surfaces of the panels 28. To assure that thepanels 28 will withstand the force imposed thereon by the bands 46, Iprefer to provide a hardwood, such as Douglas fir, inserts 48 in eachpanel 28 opposite each of the bands 46. The inserts 48 may be of anydesired configuration as long as they are suitably bonded to theinsulating wood 34 in the respective panels and provide additionalcompressive strength in the panels at the points ,of contact with theretaining bands 46. I also prefer to provide a hardwood insert 50 in theupper'and lower ends of each panel 28 to engage the base ring 12 and thecover 52, which will be hereinafter described. The hardwood inserts 50at the lower ends of the panels 28 assure that the panels 28 will not bedamaged by being supported on their ends, and the hardwoodinserts St) atboththe upper and lower ends of the panels provide protection for theinsulating wood in the panels from adverse weather.

The cover 52 may be of any desired construction, such as of thebow-string truss type using a suitable base portion 54 and a suitablenumber of trusses 56 extending upwardly in the form of bow strings fromthe opposite edges of the base portion 54. The base portion 54 and thetrusses 56 may be easily formed out of wood to provide a light-weightand economical construction. I also prefer to secure a metal shield 58over the top of the cover 52 to protect the cover from rain, snow, andthe like. The shield 58 is preferably formed out of aluminum. The cover52 is preferably insulated by suitably securing a plurality ofinsulating panels 60Qacross the bottom of the base portion 54 inside-by-side sealing engagement to provide a continuous insulation overthe lower faceof the cover. The panels 60 are shaped tofit closelyagainst the inner surfaces of the upper ends of the vertically extendingpanels 28, with the base portion 54 of the cover 52 being of a largerdiameter to rest on the tops of the panels 28. It is also desirable toapply a sealing compound between the contacting surface of the baseportion 54 of the cover and the upper ends of the panels 28 to assurethat no appreciable amount of vapor will leak from the tank around thecover.

A relatively thin lining, generally designated by reference character62, and formed out of a gas and liquidimpervious material, extendsaround the inner surfaces of the vertical panels 28 and over the upperface of .the bottom 18 to form the storage chamber for receiving coldliquid fed to the tank. The lining 62 extends loosely over the innersurfaces of the vertical panels 28 and the bottom 18 for expansion andcontraction independently of the panels 28 and the bottom 18, andcomprises a base plate 64 with a plurality of vertically superimposedan-'nular panels or rings 66 extending vertically from around the outerperiphery of the plate 64. Both the plate 64 and the panels 66 arepreferably formed out of a thin metal which will withstand thesubstantial temperature changes incurred by handling liquefied naturalgas, such as stainless steel or aluminum. However, the lining 62 may beformed out of any other material, such as a plastic, which willwithstand the temperatures involved.

The base plate 64 hasthe same configuration as the bottom 18 of the tankand is provided with at least one circumferentially extendingcorrugation 68 to accommodate expansion and contraction of the plate.The base plate 64 is also keyed to the bottom 18 to prevent the plate 64from creeping on the bottom 18 and to retain the plate 64 centered withrespect to the bottom 18.

Any desired shape of key may be used, such as a square configuration inthe center of the plate 64. However, I prefer to utilize the corrugation68 or a similar corrugation for keying the plate 64 to the bottom 18, asillustrated in Fig. 3. Thecorrugation68 is turned downwardly and looselyfits in a circumferential groove 70 formed in the upper'face of a ring72 of, for example, balsa wood. The ring 72 is in turn disposed in acircumferential groove 74fo'rmed in the upper face of the bottom 18. Itwill thusbeapparent that at least a portion of the corrugation 68 willremain in the mating groove 70 upon expansion and contraction of thebase plate 64 to retain the base plate centered with respect to thebottom 18 of the tank.

As illustrated in Fig. 1, the lower edge of the lowermost panel 66 issuitably welded or brazed around the outer periphery of the base plate64 to provide a gas and liquid-impervious connection of the lower panel66 to the base plate, This lower panel extends upwardly along the innersurfaces ofthe vertical panels 28 and is welded or brazed at its upperend to aring 76 (Fig. 4) which is preferably formed out of stainlesssteel andis T-shaped in cross section. The upperedge of the lower panel66 is welded to the downwardly extending flange of the ring j 76 and thelower edge of the next upper panel 66 is T-shaped rings 76 in the samemanner to complete the lining 62. It may also be noted that a ring 76(Fig. 1) is secured to the upper edge of the uppermost panel 66, andthis uppermost panel 66 terminates a short distance below the upper endsof the vertical panels 28.- Furthermore, each panel 66 is provided withan inwardly extending circumferential corrugation 78 in the medialportion thereofto accommodate vertical expansion and contraction of thepanels 66 without appreciably'moving the rings 76 vertically, as will bedescribed.

The lining 62 is prevented from collapsing by a supporting structure,generally designated by reference character 80, and comprising aplurality of vertically spaced wood rings 82 supported by verticallyextending wood columns 84. Each ring 82 is preferably formed out oflaminated wood and is provided with a circumferential vided for each ofthe rings 76, and the rings 76 are of a size to fit loosely within thelining 62 when the lining 62 is contracted to its smallest diameter. Thehorizontal vflange portion of each ring 76 and each groove 86 is of alength such that the ring 76 will remain extended into the respectivegroove 86 as the diameter of the lining 62 is increased and decreased byexpansion and contraction, whereby the rings 76 will be retained insubstantially fixed vertical positions by the support rings 82, yet therings 76 may slide freely in and out of the grooves 86. If desired, asoft insert 87 of balsa wood or the like may be placed in the inner endof each groove 86, as shown in Fig. 5, to cushion the force imposed onthe rings 76 in the event the rings 76 contract an excessive amount. Itshould also be noted (see Fig. 1) that each pair of the rings 76 and 82are positioned opposite the retaining bands 46 encircling the panels 28,and therein the event of excessive expansion of the rings 76.

'is positioned in the lower end of the lining 62 to provide a base forthe supporting structure 80 and prevent buckline of the lower portion ofthe lining 62.

Referring back to Fig. 1, it will be observed that the insulating panels60 secured on the bottom of the cover 56 extend outwardly over theuppermost support ring 82 and may be supported-on this ring 82 throughthe medium of a suitable insulatingpad 92 formed out of any desiredinsulating material. T

From the foregoing, it will be apparent that the presentinventionprovides a novel tank for storing cold liquids, which will belight-weight and may be economicallyconstructed. The various componentsof the tank may be shipped to the point of use disassembled and theneasily assembled in the field. In the assembly operation, the bottom 18of the tank will be assembled and the vertical panels 28 assembledaround the outer periphery of the bottom in the manner illustrated inFigs. 1 and 2. The lowermost panel 66 of the lining 62 may be weldedonto the base plate 64 and the lower supporting ring 82 assembled in thelower portion of the lining. The remaining portions of the lining 62 maythen be welded in the field while the supporting structure 80 is beingsimultaneously assembled in the lining. The entire lining 62 andsupporting structure 80 may then be inserted in the vertical panels 28onto the bottom 18 of the tank,

or, the lining 62 may be assembled in the tanks after the verticalpanels 28 have; been assembled on the bottom 18 and the base ring 12. Itwill be further apparent that the supporting structure 80 willadequately support the lining 62 in the tank and prevent collapse of thelining without placing any undue stresses on the lining. Finally, itwill be apparent that the lining 62 may contract and expand relative tothe panels 28 and the bottom 18 without placing any undue strains in theremaining tank structure and without damageto the insulation surroundingthe lining 62.

Changes may be made in the combination and arrangement of parts orelements as heretofore set forth in the specification and shown in thedrawings, it being understood that changes may be made in the preciseembed ments disclosedwithout departing from the spirit and scope of theinvention as defined in the following claims.

I claim: 1. In a tank for storing cold liquids, a bottom member, aplurality of elongated insulation panels extending upwardly from theouter periphery of the bottom and sealed in s-ide-by-side relation toform the vertical side walls of the tank, said panels being ofsufficient strength to be self-supporting,'vertically spaced retainingbands the bottom and upwardly around the inner periphery of Thesupporting columns 84 are also preferably formed out of laminated woodand are provided with vertically spaced notches 88, as shown in Figs. 4and 5, for receivthe side walls of" the tank to form a storage chamberfor receiving liquid fed to the tank, and support means positioned inthe storage chamberto prevent collapse of the lining.

2. A tank as defined-in claim 1 characterized further in that each panelcomprises a layer of insulating wood and sheets of hardwood bonded tothe inner and outer faces of the insulating wood layer.

3. Atank as defined in claim 2 characterized further to include hardwoodinserts embedded in the panels opposite the retaining bands.

4. A tank as defined in claim 2 characterized further to include ahardwood strip embedded in each side edge of each panel, and arelatively soft and tapered wood strip wedged between the mating edgesof the panels adjacent panels.

5. A tank as defined-in claim 1 characterized further in that said meansfor preventing collapse of the lining includes a plurality of wood ringsextending around the inner periphery of the lining, and vertical woodcolumns supporting the rings in vertically spaced relation in thelining.

6. In a tank for storing cold liquids, a wood base ring, a plurality ofself-supporting insulation panels extending diagonally across andsupported on the base ring to form the bottom of the tank, a pluralityof selfsupporting insulation panels extending upwardly from the basering in side-by-side relation to form the side 'walls of the tank, thelower end portions of said vertical insulation panels being securedaround the outer periphery of said tank bottom, an expansion jointbetween each pair of vertical insulation panels, a plurality ofvertically spaced retaining bands encircling the vertical insulationpanels and holding said panels in assembly, an insulated cover for thetank, and a gas and liquid-impervious lining extending loosely over thetank bottom and around the inner periphery of the tank walls to form achamber and receive cold liquid stored in the tank.

7. A tank as defined in claim 6 characterized further in that eachinsulation panel comprises a layer of insulating wood, and hardwoodsheets bonded to the inner end outer faces of the insulating wood layer.

8. A tank as defined in claim 6 wherein said lining isnon-self-supporting, and characterized further to include meanspositioned in the chamber formed by the lining to prevent collapse ofthe lining.

9. A tank as defined in claim 8 characterized further to include aplurality of vertically spaced rings interposed in the vertical portionof the lining, each of said rings in the lining having an inwardlyextending flange thereon, corrugations extending circumferentiallyaround the vlining between the rings in the lining, and characterizedfurther in that said means to prevent collapse of the lining comprises aplurality of wood support rings in the chamber formed by the lining,each of said support rings having a circumferential groove in the outerperiphery thereof, and a plurality of circumferentially spaced woodsupport columns holding each support ring concentricv with a ring in thelining and'withthe inwardly extending 'flange of each ring in the liningslidingly extending into the groove in the respective support ring;

10. A tank as defined in claim 6 characterized further in that thecentral portion of the bottom of the lining is keyed to the bottom ofthe tank to prevent creeping of the lining with contraction andexpansion of the lining -in the tank. v

11. In a tank for storing coldliquids, a non-self-supporting liningforming a chamber for receiving the cold liquid, said lining havingvertical side Walls and a bottom wall, a plurality of horizontallyextending rings secured to the side walls of the lining in verticallyspaced relation, each of said rings having an inwardly extendingcircumferential flange thereon, a plurality of Wood support ringsrigidly supported in vertically spaced relation in the in that saidsupport rings are supported by circumferentiab 1y spaced wood columns.

13. A tank as defined in claim 11 characterized further to include acircumferential corrugation in the side walls of the lining between eachpair of the flanged rings, and a circumferential corrugation in thebottom of the lining.

l 1 4. A tank as defined in claim 11 characterized further in that saidlining comprises a base plate forming the bottom wall of the lining, anda plurality of annular panels extending upwardly-in superimposedrelation above the base plate to form the side Walls of the lining, thelower edge of the lowermost annular panel being sealed to the outerperiphery of the base plate and the adjacent edges of each pair of saidannular panels being sealed to one of said flanged rings to provide agas and liquid-impervious lining.

No references cited.

